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Qixiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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Dissecting the Genome-Wide Evolution and Function of R2R3-MYB Transcription Factor Family in Rosa Chinensis.
Genes, 2019Co-Authors: Zhao Tao, Huitang Pan, Tangren Cheng, Jia Wang, Weiru Yang, Qixiang ZhangAbstract:Rosa Chinensis, an important ancestor species of Rosa hybrida, the most popular ornamental plant species worldwide, produces flowers with diverse colors and fragrances. The R2R3-MYB transcription factor family controls a wide variety of plant-specific metabolic processes, especially phenylpropanoid metabolism. Despite their importance for the ornamental value of flowers, the evolution of R2R3-MYB genes in plants has not been comprehensively characterized. In this study, 121 predicted R2R3-MYB gene sequences were identified in the rose genome. Additionally, a phylogenomic synteny network (synnet) was applied for the R2R3-MYB gene families in 35 complete plant genomes. We also analyzed the R2R3-MYB genes regarding their genomic locations, Ka/Ks ratio, encoded conserved motifs, and spatiotemporal expression. Our results indicated that R2R3-MYBs have multiple synteny clusters. The RcMYB114a gene was included in the Rosaceae-specific Cluster 54, with independent evolutionary patterns. On the basis of these results and an analysis of RcMYB114a-overexpressing tobacco leaf samples, we predicted that RcMYB114a functions in the phenylpropanoid pathway. We clarified the relationship between R2R3-MYB gene evolution and function from a new perspective. Our study data may be relevant for elucidating the regulation of floral metabolism in roses at the transcript level.
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identification of candidate adaxial abaxial related genes regulating petal expansion during flower opening in Rosa Chinensis old blush
Frontiers in Plant Science, 2019Co-Authors: Yu Han, Huitang Pan, Tangren Cheng, Jia Wang, Weiru Yang, Xue Yong, Qixiang ZhangAbstract:Petal expansion is the main process by which flower opening occurs in roses (Rosa Chinensis). Although the regulation of leaf expansion has been extensively studied, little is known about the mechanisms controlling petal expansion. The regulation of leaf dorsoventral (adaxial-abaxial) polarity is important for blade expansion and morphogenesis, but the mechanisms involved adaxial-abaxial regulation in petals are unknown. We found that auxin, a key hormonal regulator of leaf adaxial-abaxial patterning, is unevenly distributed in rose petals. The transcriptomes of the adaxial and abaxial petal tissues were sequenced at three developmental stages during flower opening. Genes that were differentially expressed between the two tissues were filtered for those known to be involved in petal expansion and phytohormone biosynthesis, transport, and signaling, revealing potential roles in petal expansion, especially auxin pathway genes. Using a weighted gene coexpression network analysis (WGCNA), we identified two gene modules that may involve in adaxial-abaxial regulation, 21 and five hub genes have been found respectively. The qRT-PCR validation results were consistent with the RNA-seq data. Based on these findings, we propose a simple network of adaxial-abaxial-related genes that regulates petal expansion in R. Chinensis "Old Blush." For the first time, we report the adaxial-abaxial transcriptional changes that occur during petal expansion, providing a reference for the study of the regulation of polarity in plant development.
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RcAP1, a Homolog of APETALA1, is Associated with Flower Bud Differentiation and Floral Organ Morphogenesis in Rosa Chinensis.
International journal of molecular sciences, 2019Co-Authors: Aoying Tang, Huitang Pan, Tangren Cheng, Jia Wang, Weiru Yang, Qixiang ZhangAbstract:Rosa Chinensis is one of the most popular flower plants worldwide. The recurrent flowering trait greatly enhances the ornamental value of roses, and is the result of the constant formation of new flower buds. Flower bud differentiation has always been a major topic of interest among researchers. The APETALA1 (AP1) MADS-box (Mcm1, Agamous, Deficiens and SRF) transcription factor-encoding gene is important for the formation of the floral meristem and floral organs. However, research on the rose AP1 gene has been limited. Thus, we isolated AP1 from Rosa Chinensis ‘Old Blush’. An expression analysis revealed that RcAP1 was not expressed before the floral primordia formation stage in flower buds. The overexpression of RcAP1 in Arabidopsis thaliana resulted in an early-flowering phenotype. Additionally, the virus-induced down-regulation of RcAP1 expression delayed flowering in ‘Old Blush’. Moreover, RcAP1 was specifically expressed in the sepals of floral organs, while its expression was down-regulated in abnormal sepals and leaf-like organs. These observations suggest that RcAP1 may contribute to rose bud differentiation as well as floral organ morphogenesis, especially the sepals. These results may help for further characterization of the regulatory mechanisms of the recurrent flowering trait in rose.
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Comparative transcriptome analysis of the floral transition in Rosa Chinensis 'Old Blush' and R. odorata var. gigantea.
Scientific reports, 2017Co-Authors: Xuelian Guo, Le Luo, Huihua Wan, Huitang Pan, Tangren Cheng, Jia Wang, Qixiang ZhangAbstract:The floral transition is a crucial developmental event, but little is known about the underlying regulatory networks in seasonally and continuously flowering roses. In this study, we compared the genetic basis of flowering in two rose species, Rosa Chinensis ‘Old Blush’, which flowers continuously, and R. odorata var. gigantea, which blooms in early spring. Gene ontology (GO) terms related to methylation, light reaction, and starch metabolism were enriched in R. odorata var. gigantea and terms associated with sugar metabolism were enriched in R. Chinensis ‘Old Blush’ during the floral transition. A MapMan analysis revealed that genes involved in hormone signaling mediate the floral transition in both taxa. Furthermore, differentially expressed genes (DEGs) involved in vernalization, photoperiod, gibberellin (GA), and starch metabolism pathways converged on integrators, e.g., LFY, AGL24, SOC1, CAL, and COLs, to regulate the floral transition in R. odorata var. gigantea, while DEGs related to photoperiod, sugar metabolism, and GA pathways, including COL16, LFY, AGL11, 6PGDH, GASA4, and BAM, modulated the floral transition in R. Chinensis ‘Old Blush.’ Our analysis of the genes underlying the floral transition in roses with different patterns of flowering provides a basis for further functional studies.
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Transcriptome of the floral transition in Rosa Chinensis ‘Old Blush’
BMC genomics, 2017Co-Authors: Xuelian Guo, Le Luo, Huihua Wan, Ni Zhen, Jiongrui Tan, Huitang Pan, Qixiang ZhangAbstract:The floral transition plays a vital role in the life of ornamental plants. Despite progress in model plants, the molecular mechanisms of flowering regulation remain unknown in perennial plants. Rosa Chinensis ‘Old Blush’ is a unique plant that can flower continuously year-round. In this study, gene expression profiles associated with the flowering transition were comprehensively analyzed during floral transition in the rose. According to the transcriptomic profiles, 85,663 unigenes and 1,637 differentially expressed genes (DEGs) were identified, among which 32 unigenes were involved in the circadian clock, sugar metabolism, hormone, and autonomous pathways. A hypothetical model for the regulation of floral transition was proposed in which the candidate genes function synergistically the floral transition process. Hormone contents and biosynthesis and metabolism genes fluctuated during the rose floral transition process. Gibberellins (GAs) inhibited rose floral transition, the content of GAs gradually decreased and GA2ox and SCL13 were upregulated from vegetative (VM) meristem to floral meristem (FM). Auxin plays an affirmative part in mediating floral transition, auxin content and auxin-related gene expression levels were gradually upregulated during the floral transition of the rose. However, ABA content and ABA signal genes were gradually downregulated, suggesting that ABA passively regulates the rose floral transition by participating in sugar signaling. Furthermore, sugar content and sugar metabolism genes increased during floral transition in the rose, which may be a further florigenic signal that activates floral transition. Additionally, FRI, FY, DRM1, ELIP, COP1, CO, and COL16 are involved in the circadian clock and autonomous pathway, respectively, and they play a positively activating role in regulating floral transition. Overall, physiological changes associated with genes involved in the circadian clock or autonomous pathway collectively regulated the rose floral transition. Our results summarize a valuable collective of gene expression profiles characterizing the rose floral transition. The DEGs are candidates for functional analyses of genes affecting the floral transition in the rose, which is a precious resource that reveals the molecular mechanism of mediating floral transition in other perennial plants.
Xing-yao Xiong - One of the best experts on this subject based on the ideXlab platform.
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Co-expression of MtDREB1C and RcXET Enhances Stress Tolerance of Transgenic China Rose (Rosa Chinensis Jacq.)
Journal of Plant Growth Regulation, 2016Co-Authors: Ji-ren Chen, Rong Liu, Zi-niu Deng, Yan-bin Chen, Monika Ziemiańska, Irena Niedźwiecka-filipiak, Jin-xia Jiao, Xing-yao XiongAbstract:The xyloglucan endotransglycosylase gene RcXET of China Rose (Rosa Chinensis Jacq.) and the MtDREB1C gene of Medicago truncatula Gaertn. were pyramided into the plant expression vector pBin438 and transformed into China Rose. Southern blot and Northern blot analyses showed that the heterologous gene MtDREB1C was integrated into the genome of surviving transgenic rose plants and expressed at different levels. Real-time PCR analysis demonstrated that robust expression of the congenetic gene RcXET was activated in the five surviving transgenic rose plants. The performance of the five transgenic lines under freezing and drought stress was superior to that of non-transformed controls. Thus, pyramiding of the genes MtDREB1C and RcXET in China Rose was more effective to enhance freezing and drought tolerance than untransformed controls. A positive correlation was observed between the expression of RcXET and the growth rate in contrast to the non-transgenic plants. The physiological assay showed that co-expression had greater effects on EC%, contents of proline, soluble sugar, photosynthesis rate, negative water potential, and turgor loss point than activities of POD and SOD under stress. The study also highlights the utility of a simple and rapid approach to express two or even more genes in one expression vector.
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The Influence of Plant Growth Regulators and Light Quality on Somatic Embryogenesis in China Rose (Rosa Chinensis Jacq.)
Journal of Plant Growth Regulation, 2013Co-Authors: Ji-ren Chen, Rong Liu, Zi-niu Deng, Xing-yao XiongAbstract:We investigated the effect of red light and plant growth regulators on somatic embryogenesis in China Rose (Rosa Chinensis Jacq.). Embryogenic calli that had been induced by combinations of 2,4-dichlorophenoxyacetic acid and thidiazuron in darkness were exposed to dark, red, and white light treatments. Cultures subjected to red light treatment generated the greatest number of embryos, with one (SE1 embryos) or two (SE2 embryos) expanded cotyledons. The largest numbers of shoot-like embryos without cotyledons (SE0 embryos) were produced in cultures subjected to dark treatment. The effects of different concentrations of abscisic acid (ABA) on the proliferation and germination of different types of somatic embryos were also evaluated. A concentration of 9.45 μM was found to be the most effective in promoting the proliferation and germination of SE2 embryos. The higher the concentration of ABA (from 0 to 18.90 μM), the higher the percentage of abnormal polycotyledonary embryos produced. The highest percentage of regenerated plants was obtained from SE2 embryos.
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DREB1C from Medicago truncatula enhances freezing tolerance in transgenic M. truncatula and China Rose ( Rosa Chinensis Jacq.)
Plant Growth Regulation, 2010Co-Authors: Ji-ren Chen, Rong Liu, Xing-yao Xiong, Tian-xiang Wang, Shou-yi Chen, Lan-bin Guo, Hua-fang WangAbstract:We isolated a DREB orthologue, MtDREB1C, from Medicago truncatula. Its deduced protein contains an AP2 domain of 57 amino acids. Yeast one-hybrid assay revealed that MtDREB1C specifically bound to the dehydration-responsive element (DRE) and activated the expression of HIS3 and LacZ reporter genes. In a transcriptional activation assay, coexpression of the MtDREB1C cDNA resulted in much higher (21.2 times) transactivation of the LacZ reporter gene than experiments performed without MtDREB1C. Transformation of Medicago revealed that overexpression of MtDREB1C suppressed shoot growth, and enhanced the freezing tolerance of M. truncatula. The MtDREB1C gene was transformed into China Rose (Rosa Chinensis Jacq.) driven by Arabidopsisrd29A promoter. Southern-blot analysis showed that the target gene was integrated into the genome of a surviving transgenic rose plant. Northern-blot analysis illustrated that robust expression of MtDREB1C was only activated under stress conditions, and the expressed MtDREB1C mRNA reached maximum accumulation 10 h following freezing treatment. The performance of the transgenic line under freezing stress was superior to untransformed controls. This transgenic plant continued to grow, flowered under unstressed conditions, and was phenotypically normal. These facts indicate that the MtDREB1C gene, isolated from Medicago truncatula and driven by the Arabidopsis rd29A promoter, enhanced freezing tolerance in transgenic China Rose significantly without any obvious morphological or developmental abnormality.
Mohammed Bendahmane - One of the best experts on this subject based on the ideXlab platform.
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The Rosa Chinensis cv. viridiflora phyllody phenotype Is associated with misexpression of flower organ identity genes
Frontiers in Plant Science, 2016Co-Authors: Huijun Yan, Hao Zhang, Sylvie Baudino, Qigang Wang, Hongying Jian, Xianqin Qiu, Jeremy Just, Olivier Raymond, Jihua Wang, Mohammed BendahmaneAbstract:Phyllody is a flower abnormality in which leaf-like structures replace flower organs in all whorls. Here, we investigated the origin and the molecular mechanism of phyllody phenotype in Rosa Chinensis cv. Viridiflora, an ancient naturally occurring Chinese mutant cultivar. Reciprocal grafting experiments and microscopy analyses, demonstrated that the phyllody phenotype in Viridiflora is not associated with phytoplasmas infection. Transcriptome comparisons by the mean of RNA-Seq identified 672 up regulated and 666 down-regulated genes in Viridiflora compared to its closely related genotype R. Chinensis cv. Old Blush. A fraction of these genes are putative homologs of genes known to be involved in flower initiation and development. We show that in flower whorl 2 of Viridiflora, a down-regulation of the floral organ identity genes RcPISTILLATA (RcPI), RcAPETALA3 (RcAP3) and RcSEPALLATA3 (RcSEP3), together with an up -regulation of the putative homolog of the gene SUPPRESSOR of OVEREXPRESSION of CONSTANS1 (RcSOC1) are likely at the origin of the loss of petal identity and leaf -like structures formation. In whorl 3 of Viridiflora, ectopic expression of RcAPETALA2 (RcAP2) along with the down regulation of RcPI, RcAP3, and RcSEP3 is associated with loss of stamens identity and leaf -like structures formation. In whorl 4, the ectopic expression of RcAP2 associated with a down -regulation of RcSEP3 and of the C-class gene RcAGAMOUS correlate with loss of pistil identity. The latter also suggested the antagonist effect between the A and C class genes in the rose. Together, these data suggest that modified expression of the ABCE flower organ identity genes is associated with the phyllody phenotype in the rose Viridiflora and that these genes are important for normal flower organs development.
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Transcriptome and gene expression analysis during flower blooming in Rosa Chinensis 'Pallida'.
Gene, 2014Co-Authors: Yan Huijun, Li Shubin, Jian Hongying, Chen Min, Mohammed Bendahmane, Hao Zhang, Sylvie Baudino, Jean-claude Caissard, Zhang Ting, Zhou NingningAbstract:Abstract Rosa Chinensis ‘Pallida’ (Rosa L.) is one of the most important ancient rose cultivars originating from China. It contributed the ‘tea scent’ trait to modern roses. However, little information is available on the gene regulatory networks involved in scent biosynthesis and metabolism in Rosa. In this study, the transcriptome of R. Chinensis ‘Pallida’ petals at different developmental stages, from flower buds to senescent flowers, was investigated using Illumina sequencing technology. De novo assembly generated 89,614 clusters with an average length of 428 bp. Based on sequence similarity search with known proteins, 62.9% of total clusters were annotated. Out of these annotated transcripts, 25,705 and 37,159 sequences were assigned to gene ontology and clusters of orthologous groups, respectively. The dataset provides information on transcripts putatively associated with known scent metabolic pathways. Digital gene expression (DGE) was obtained using RNA samples from flower bud, open flower and senescent flower stages. Comparative DGE and quantitative real time PCR permitted the identification of five transcripts encoding proteins putatively associated with scent biosynthesis in roses. The study provides a foundation for scent-related gene discovery in roses.
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Somatic embryogenesis and transformation of the diploid Rosa Chinensis cv Old Blush
Plant Cell Tissue and Organ Culture, 2010Co-Authors: Philippe Vergne, Marion Maene, Guillaume Gabant, Aurélie Chauvet, Thomas Debener, Mohammed BendahmaneAbstract:Somatic embryogenesis was induced from in vitro-derived leaf explants of Rosa Chinensis cultivar (cv) Old Blush. Calli producing embryos with expanded cotyledons (RcOBType1 embryos) were obtained. Further refinements of the callus maintenance medium generated a more typical rose embryogenic callus (RcOBType2) displaying high levels of secondary embryogenesis and embryos with limited cotyledon expansion Agrobacterium tumefaciens-mediated transformation assays using β-glucuronidase (GUS) reporter gene showed that both types of embryos were competent for transformation. Under selection conditions, transformed RcOBType1 explants produced non chimaeric transformed embryos, from which shoots could be adventitiously regenerated. In contrast to RcOBType1, transformed RcOBType2 embryos directly yielded transformed shoots when repeatedly cultured in selective regeneration conditions. Transformation efficiency ranged between three to nine percent and shoots suitable for rooting were obtained within 6-8 months. Transgenic plants were transferred into the greenhouse and molecularly confirmed. The availability of transformation methods in a diploid rose, R. Chinensis cv. Old Blush, will be useful for gene functional studies.
Agnès Grapin - One of the best experts on this subject based on the ideXlab platform.
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Cryopreservation of ex-vitro-grown Rosa Chinensis 'Old Blush' buds using droplet-vitrification and encapsulation-dehydration
Plant Cell Tissue and Organ Culture, 2014Co-Authors: Camille Le Bras, Pierre-henri Le Besnerais, Latifa Hamama, Agnès GrapinAbstract:Axillary buds from greenhouse-grown plants of Rosa Chinensis 'Old Blush' were successfully used to establish cryopreservation protocols using both droplet-vitrification and encapsulation-dehydration methods. In droplet vitrification, regrowth occurred after exposure to liquid nitrogen even without pre-culture in the loading solution (LS) before immersion in the plant vitrification solution 2 (PVS2). However, a 20-80 min LS step followed by a short immersion in PVS2 for 3 or 15 min, at 0 A degrees C gave the best regrowth rates (82-86 %). In encapsulation dehydration, the level of dehydration significantly influenced shoot regrowth. The best regrowth rate, 60 %, was obtained at a bead water content of 0.35 g water per g dry weight. These results demonstrate the possibility of using greenhouse plants of rose for cryopreservation by droplet vitrification and encapsulation dehydration.
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Cryopreservation of ex-vitro-grown Rosa Chinensis ‘Old Blush’ buds using droplet-vitrification and encapsulation-dehydration
Plant Cell Tissue and Organ Culture (PCTOC), 2013Co-Authors: Camille Le Bras, Pierre-henri Le Besnerais, Latifa Hamama, Agnès GrapinAbstract:Axillary buds from greenhouse-grown plants of Rosa Chinensis ‘Old Blush’ were successfully used to establish cryopreservation protocols using both droplet-vitrification and encapsulation-dehydration methods. In droplet vitrification, regrowth occurred after exposure to liquid nitrogen even without pre-culture in the loading solution (LS) before immersion in the plant vitrification solution 2 (PVS2). However, a 20–80 min LS step followed by a short immersion in PVS2 for 3 or 15 min, at 0 °C gave the best regrowth rates (82–86 %). In encapsulation dehydration, the level of dehydration significantly influenced shoot regrowth. The best regrowth rate, 60 %, was obtained at a bead water content of 0.35 g water per g dry weight. These results demonstrate the possibility of using greenhouse plants of rose for cryopreservation by droplet vitrification and encapsulation dehydration.
Gui-xia Jia - One of the best experts on this subject based on the ideXlab platform.
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Genome-wide transcriptome analysis of the salt stress tolerance mechanism in Rosa Chinensis.
PloS one, 2018Co-Authors: Tian Xiaoming, Wang Zhenyu, Zhang Qing, Ci Huacong, Wang Pengshan, Gui-xia JiaAbstract:Plants regulate responses to salt stress using biological pathways, such as signal perception and transduction, photosynthesis, and energy metabolism. Little is known about the genetics of salt tolerance in Rosa Chinensis. Tineke and Hiogi are salt-tolerant and salt-sensitive varieties of R. Chinensis, respectively, and are good choices for studying salt-tolerance genes. We studied leaf and root tissues from 1-year-old Hiogi and Tineke plants simultaneously grown under the same conditions. A 0.4%-mmol/L salt ion mixture was added to the basic growth medium. Illumina sequencing was used to identify differentially expressed transcripts. GO and KEGG pathway enrichment analyses were performed to identify differentially expressed genes. We identified many differentially expressed genes associated with salt tolerance. The abscisic acid-dependent signaling pathway was the main pathway that mediated the salt stress response in R. Chinensis. Two pathways (plant hormone signal transduction and glutathione metabolism) were also active in salt stress responses in R. Chinensis. The difference in salt tolerance in the cultivars was due to different gene sensitivity to salt in these two pathways. Roots also play a role in salt stress response. The effects of salt stress in the roots are eventually manifested in the leaves, causing changes in processes such as photosynthesis, which eventually result in leaf wilting. In Tineke, Snrk2, ABF, HSP, GSTs, and GSH1 showed high activity during salt stress, indicating that these genes are markers of salt tolerance.
